1. Field of the Invention
The present invention relates to a rear window stop lamp which may selectively be mounted on the rear window of a motor vehicle and which, when mounted on the rear window, can be energized in response to the application of the brake of the motor vehicle.
2. Description of the Relevant Art
There have recently proposed motor vehicles having a stop lamp mounted as an optional lamp on the upper edge of a rear window in addition to ordinary rear stop lamps which can be energized when the brake of the motor vehicle is applied. One such a rear window stop lamp is disclosed in Japanese Laid-Open Utility Model Publication No. 61-129631, for example. The disclosed rear window stop lamp comprises a plurality of bullet-shaped LEDs housed in a case and directed rearwardly. Light beams emitted by the LEDs are converted by a lens plate into parallel light beams that are directed rearwardly.
Since the light beams emitted by the LEDs of the disclosed rear window stop lamp are directed rearwardly as parallel light beams, it is necessary that the lens plate be disposed in a position which is spaced from the LEDs by a distance equal to the focal length of the lens plate. Therefore, the width of the stop lamp in the longitudinal direction of the motor vehicle is relatively large. As a result, the space between the rear seat of the motor vehicle and the rear window stop lamp is relatively small, and the appearance of the rear window as viewed from within the passenger's compartment of the motor vehicle is unsightly. Another problem is that the rear window stop lamp may easily be reached and tampered with by children who sit on the rear seat.
Generally, the covers or cases of rear window stop lamps are made of a synthetic resin such as polycarbonate resin. When sunlight is directly applied to the rear window stop lamp covers, they tend to be thermally expanded at a rate different from the rate of thermal expansion of the glass of the rear window, resulting in undue shearing stresses developed in the junction between the cover and the window glass.
The polycarbonate resin is relatively hard and cannot easily be bent over. If a cover or case of polycarbonate resin is shaped to a sheet of rear window glass of a particular design, then it cannot be used with a sheet of rear window glass of other designs or shapes. Accordingly, the conventional rear window stop lamp cases or covers of polycarbonate resin are comparatively expensive.
The present invention has been made in an effort to solve the above problems of the conventional rear window stop lamps for use on motor vehicles.